A lemon = a piece of junk. It's doesn't work, or it doesn't work properly, or it has a lot of problems. We usually call something a "lemon" if it's already broken when you buy it (not because of something you did to it, or something that happened to it after you bought it). Using "lemon" this way is slang, but it's pretty common, at least in the US. It's most often used for talking about cars, but you can also call other things "lemons," especially electronic items. For example, if you bought a new phone, but the battery wouldn't stay charged for more than a few hours, you might say "It looks like I got a lemon." It means you got a defective phone. (You'd probably try to return it to the store and get your money back.)

Hi Mikhail! Lemon= faulty A defective car.

It's a metaphor. That means you are comparing the car to a lemon, but when you use metaphor, you don't say it is like a lemon. You say it is a lemon. You could say it's like a lemon, but that wouldn't be metaphor. It would be something else. A lemon is a fruit. It might look nice, but if you use it, it will leave a sour taste in your mouth. A lemon is a car that looked good, but has been nothing but trouble. It breaks down. It needed a new gearbox. You regret buying it.

Anything that was not made to work well when it came from the factory. In some states we have "lemon laws" if you buy a car that immediately has very severe problems. You can get your money back if they declare it "a lemon". I returned a computer to Apple because it was a lemon. Also another time, Apple decided my computer had had to have too many repairs and it was cheaper for them to declar4e it a lemon and give me a new computer.

This is worrying. A couple of months ago I bought a new (second-hand) car. It is lemon yellow. The other colours were too expensive... The garage man who sold it to me assured me that it would be be a great car and very reliable. Tomorrow it is going to have its annual official check up (MOT in the UK). If it turns out to be a lemon and I have to spend a fortune fixing it up, I will go bananas. (True story... Sorry about the corny joke; I couldn't resist...)